| difficult(adjective, hard, tough, troubled, problematic) |
| severe(tough, painful, problematic, trying) |
| arduous(tough, severe, painful, problematic, trying) |
| demanding(tough, severe, painful, problematic, trying) |
| difficile(tough, severe, painful, problematic, trying) |
| exacting(tough, severe, painful, problematic, trying) |
| laborious(tough, severe, painful, problematic, trying) |
| no picnic(expression, tough, severe, painful, problematic) |
| operose(tough, severe, painful, problematic, trying) |
| strenuous(tough, severe, difficult, painful, troubled) |
| titanic(tough, severe, painful, problematic, trying) |
| toilsome(tough, severe, painful, problematic, trying) |
| tough(severe, difficult, painful, troubled, problematic) |
| trying(tough, severe, difficult, painful, troubled) |
| uphill(tough, severe, painful, problematic, trying) |
| wretched |
| abstruse |
| adverse |
| ambitious(tough, severe, painful, problematic, trying) |
| antagonistic |